Web scanning device



Jan. 11, 1949. I fo, ss 2,458,926

WEB SCANNING DEVICE Filed March 12, 1948 Inventor" 2 l Mwcm o. Baa-56 Gb1 WW His Attorney.

Patented Jan. 11, 1949 UNITED STATE New York 7 Application March 12,1948, Serial N... 14, 133

faciaims. (o1. 25.1-41.5) Y

My invention relates to web scanning devices utilized in connection witha continuously moving web and is related, more particularly, to suchdevices utilizing light sensitive means responsive to light reflectedfrom or transmitted through such continuously moving web. J j

A principal object of my invention is to provide an improved device ofthe type described which requires very simple manipulation thereof to accomplish scanning of a continuously moving web by specularly ordifiusely reflected light from said movingweb.

' Another object of the type described which is economical to"manufacture and is adapted to be operatedby personnel having a minimumof skill. z

In general, my invention comprises an enclosure which supports within ita pivotal chassis. Mounted on the chassis are alamp and a'photoelectrictube separated by a partition to keep the direct rays of the lamp fromentering the proto-; electric tube. The light from the lamp is directedthrough a lens systemsecured to thepartition to provide a sharplyfocused area or spot of light on a moving web. As arrari'gedQthemovement of" the chassis moves the locus of thefocalpoint of light alongan are between selected positions so as to provide either diffuse orspecular reflect-ion of said lightfrom the moving web. The point ofpivot is so disposed with respect to the moving web that the light imageincident on the web is in' substantial focus at either the difiuseorspecular position. a

The advantage of the above recited arrange ment of my invention is inproviding a relatively fixed enclosure, and Without disturbing theposition of this enclosure with respect to the webbeing scanned, providea change from diffuse reflection to specular or back as desired. This isaccomp-' lished by rotating the chassis through a pre -j determined arcand causing the spot of light incident on the moving web toshift alongsaid arc between predetermined points so as to alter the angle ofreflection with respect to the moving web. The above objects and otheradvantages of my invention will be better understood from the followingdescription and accompanying drawing. in which Fig. 1 is a side view ofan embodiment of my invention with the enclosures broken" away toillustratethe arrangement of the components therein; Fig. 2 is a frontview. of my device with the upper enclosure in cross sectiontoillustrate the cooperative arrangement of components for operation ofthe device when utilized for diffusely.

reflected light; Fig. 3 is a second front view with WEB SCANNING DEVICEMerton 0. Bassett, Schenectady, N. Y., assignor" to General ElectricComp any a corporation or is to provide an improvedf'device s I mar-itheupper and a portion of the lowerenclosures in cross section toillustrate the utilization of my device for transmitted orspecularlyreflected light; Fig. 4 illustrates the utilization o suitable indiciafor indicating the operatin vpositions .of my device Fig. 5 depictsasimplified perspective view illustrating thefapplication of mydevice,for, scanning a moving web; and Fig. Sis a schematic diagram showingthe electrical connections .of my device. j p In the description tofollowrthe term web is defined as any fiat sheet or ribbon materialsuchas paper, cellulose nitrate material (opaqueor transparent) rubbersheets, metal foil, wood and g i" Theterm light-sensitivedevice?includes such devices as photoelectric tubes of the soft orgas filledtypes, electron-multipliertypes; bolometer's; photolytic .cells,selenium cells, and like devices;

Referring to the drawing, my scanning head 10- comprises an enclosure-Hcontaininga-movable chassis l2 arranged to pivot about'a point' l3asshowninFigs.2and3.

Movement of the chassis -I2 is manipulation of a thumbscrew l4attached-to an extended portion [5 of the chassis, the -thumb.

screw passing throughya slot provided for. this purpose in thefrontportion l! of the enclosure l'l. Fig. 4 is a fragmentary view of;the-portion I] with suitable operatingindicia inscribed there- .Mountedupon the chassis |2is a light .source I8, for example, aconventionalautomobile"head light lamp. This type-of light source ispreferred;

light'source 24 of the'same type asl8... Th ligl'it source 24 isdisposed in an enclosure 25, the en,-

closurebeing secured to the scanning head I [l'bymeans of a connectionplug 26 attached to the enclosure 25 for engagement with a receptacle2'! attached to said scanning head as shown: in Fig. 1.

A single-pole, double throw switch 28 ,is

utnizea to switch the power from the light source accomplished byv l8 tothe light source 24 or vice versa at will. A suitable source of electriccurrent supply (not shown) is fed through a connector 29 to energizeboth light sources I8 and 24 and the photoelectric tube [9.

3 An aperture, 30 is provided in the enclosure 25 so that a beam oflight of proper size and shape reaches thephgtoelectric tube .1 8 A inthe scopedff'jmsifir'ifvnfiion torutiligelanadifisfi able aperture if sodesired.

The power supply circuit is very simple, as illus- H I the componentsfor transmitted light operation trated in Fig. 6, and is one whichrequires a mi mum of labor to assemble.

When, as shown in Fig. 5 a suitably disposed in relati a e: 22 and thechassis I2 rotated to th of thelightimagereacliesthe photoelectrig tube.

di" t .5 l. l fen le se .sibse iieiw wus tl ,.t l er-positibn Ani-the'iccus'dr-eucfdcar bnit Being r the are etveq gihe r leased Bgm maic a new i h a ieeiib enc ure l! e a n s et fi'fl wuiis-tiie ehsngeffistbisl e luai-geneaticnsisamaee by -ii pi Shir be ppreciate th atarrangement req'u as a mihlinum ofliiiarifpulati by terator a niihimuiiicesium 7? Inasmuch as the application of my deviceis suits-bre-tethesemfihg ef w eb ct fiposee friii'ah amrx' an' usiiiateriais: th acptaunitgt ero examplefiiion is rr e em or'rly requirement" istlle d series ofmarks vide a siiijfac ljf w 315 h i. scar'i is changew'to provide d th eisci l hil r moving issalso with 6 651 an" illustrated in Fig. 2, thelight source image will appear on the web 22 at a poiriiiii? Iiiears-tbsp tion, the specular light image is directedsbaclg into the lenssystem andlonly the difiusereflection ea e 4 or no light will reach thephotoelectric tube thereby providing a similar current response in thephotoelectric tube as described above.

For scanning transparent web, direct transmission of light is utilizedand the web is marked with an opaque substance. The switch 28 is thrownto the right (with respect to the observer) as illustrated in 4, and'the thumbl screw 14 nipyed under; the :arrow toi'tl're right oftheinscription Transmitted light. This position is similar to specularscan. The relative position of operate,

large variety oi material, compact and economical j I 'heiembodiment ofmy invention which has been illustrated and described has been selectediorthe purpose of setting forth the principles involyledli Itlwill beobvious that my invention maybe modifi'edftomeet various conditions fordifferentspe'cific uses, audit is, therefore, intendedltol' cover'by theappended claims all such modifications which fall within the spirit andscope of this invention.

What/IQ-cl aim as new and desire'to secure by Letters'Batent of theUnited States is:

1.. ma photoelectric device for scanning a moving. web,-. a pivotal.support. having mounted thereon a photoelectric tube and an opticalsystem, said'optical system projecting a-lightimage on. said "web andcomprising a. light source and focusing. means between said light sourceand said web, andvnieans for moving said pivotal supportbetweenftwopredeterminedpositions to shift saidl'ghtimage on said web,said/positionsbeiue' such that he, photoelectric tube receives'diffuselyrefiected-light in one said position and specularlyreflectedlight in the other said position;

2111 aphotoelectric device for scanning a moving web; a; pivotal supporthaving mounted thereon: a photoelectric tube and: an optical systern;saidopticalzsystem projecting alight image on said-{web andcomprising'a; light source and focusing; means between'said light sourceand said) web;, and means for rotating said pivotal supporthetweenpredetermined-positions to cause movement cf the light ima e along elsne .Q se qim v ne we 3. In a photoelectric device for scanning amoving web, a pivota-l support having mounted an arc in thereon aphotoelectric tube and an optical system, said optical system projectingalight image on web: and comprising a light source and tocusingmeansbetween said light source and sai web, and means for moving saidpivotal sup- 1 port;betweenv two spaced-apart predetermined positions toshift said light image on said web, said position; being such. that saidphotoelectric tube receives'difiusfly reflected light in one position.and specularly reflected light. in the other position, saidpivotalsupport being so disposed with'respect tosaid web that said light imageis 'i ,'resm 1 said. Web in either of said posiees- 4. In a;photoelectric device for scanning a moving web; a pivotal support,apartition of opaque materialmounted on said support; an opticalfsystemprojecting a light image on said web andj comprising a light sourcesecured to saidfsuppoi tongone side of said partition, focusng-.. sensauce 9 itd Par t diate said light source and moving web. a lightsensitive device secured to said support on: the other side of saidpartition, and means for rotat ing said pivotal support betweenpredetermined positions to cause movement of the light image along anarc in the plane of said moving web;

5. In a photoelectric device for scanning a moving web, a pivotalsupport having mounted thereon a photoelectric tube and an opticalsystem, said optical system projecting a light image on one side of saidweb and comprising a light source and focusing means between said light(No references cited.)

